Abstract
We carried out heating experiments of chlorophyll-a alone and in the presence of clay or water in order to obtain useful information on its degradation in the early diagenesis in sediments. The heating experiments showed that the degradation proceeded in the order of chlorophyll-a with clay < chlorophyll-a alone < chlorophyll-a with water. The activation energies estimated were 36.2kcal/mol for chlorophyll-a alone, 38.3kcal/mol for chlorophyll-a with clay, and 21.0kcal/mol with water. The transformation pathway of chlorophyll-a to pyropheophorbide-a was different if water was present. Heating of chlorophyll-a alone and with clay released the phytyl chain in the first step, while demetallation preceded in case of chlorophyll-a with water.
